This invention, in one of its aspects, pertains to automatic hair shampoo machines. In another of its aspects the invention pertains to improvements in the apparatus characterized in my earlier U.S. Pat. No. 3,521,647.
The invention which was the basis of my U.S. Pat. No. 3,521,647 overcame the problems associated with prior automatic shampoo machines, particularly those with scalp massaging devices, such as those described in U.S. Pat. Nos. 2,566,600, 2,854,969, 2,854,970 and 3,177,868. However my invention did have some disadvantages.
By eliminating scalp massaging devices, based on the discovery that the massaging action can be obtained by jets of solution moving across the head, I introduced into industrial channels automatic shampoo machines previously not commercialized. When commercialization of U.S. Pat. No. 3,521,647 was undertaken it became apparent that fixed headers operated in sequence did not produce the same scalp stimulation which the moving header did. Hence it was the moving header of U.S. Pat. No. 3,521,647 which was commercialized. As the commercialization progressed, certain unforseeable limitations slowly surfaced. It was not until after a large number of hair washings that it was found that in the machine of my previous patent the washing action was not quite that desired. The reason for this is an apogee-perigee effect which will be explained hereinafter. At this point it will suffice to point out that the apogee-perigee effect produces skips or gaps in spray, turbulent conditions, and coalescence of spray droplets, all of which inhibit the washing action.
It was assumed that if there were gaps or skips in spray, whatever the reason, detergent water surging across hair so skipped by spray would nevertheless wash it. Since to some extent this is true, the imperfect washing went unnoticed. When the flaw did become apparent, it was solved by moving the header swivel joint, or axis of rotation, above and outside the bowl. With the swivel connection outside the bowl so that the header oscillated about an axis through the head, and more or less parallel thereto, electrical and mechanical problems arose. It was difficult to keep water out of the drive mechanism, and hair out of the swivel joint.
Contrary to expectations increasing the pressure of solutions being sprayed does not improve the washing action. In addition too much pressure can be discomfortable. It can also lead to a turbulent condition. If the pressure is increased to obtain sufficient jet action for underneath washing, impingement on the scalp is too intense and turbulance can become too great. Thus, the washing power of my prior invention was subject to improvement, but such improvements did not come into being. It became apparent that the swivel joint had to be in the bowl. With the axis in the bowl solutions to the problem of imperfect washing could not be found. They are the subject of one aspect of this invention.
In another aspect of this invention, during the time the apparatus of U.S. Pat. No. 3,521,647 was in service, it became apparent that the use of tanks or reservoirs for hair treating solutions imposed severe limitations on the use of the apparatus. Shampoo reservoirs, such as those in my apparatus, and in U.S. Pat. Nos. 2,854,969, 2,854,970 and 2,185,495 are of limited capacity. This means that the shampoo tanks frequently had to be refilled. As a consequence the machines could not be left unattended. During all the years of use no solution could be found to the tank problem. As a result the machines have not been installed in nursing and retirement centers. In addition the type and hardness of water used in the machine imposed constraints on mixing the shampoo and water for use in the solution tanks. The mixing of hair treating solutions with water also required the attendant. Consequently my earlier invention was in need of improvement, but such improvements were not forthcoming. By the improvement herein a hair shampoo machine is provided which can be used unattended. I have solved the long-existing tank problem.
One other imperfection in my U.S. Pat. No. 3,521,647 apparatus was that no drying means was provided. In installations for senor citizens dryers are a necessity. With no attendant present, commercial drying units were not feasible. They are large, rather overwhelming, and somewhat complex. Lack of drying means was found to militate against the use of my automatic shampoo machines in health care and retirement centers. In still another aspect of this invention hair drying means have been incorporated in the automatic shampoo machine.